From the incipience of disposable absorbent articles for sanitary applications on infants, and subsequently to alleviate problems of incontinency in adults, manufacturers of these products have focused over a long period of time on a continual improvement in the fabrication of the absorbent core, conforming to traditional methods in the design of gripping elements to adjust the product to the user's body and the comfort provided to them.
Babies and other incontinent individuals use absorbent articles, such as diapers, to receive and contain urine and other body eliminations. Absorbent articles operate both to contain materials eliminated from the body and absorb discharges from the user's body and avoid leaking and spotting of the user's garments and bed clothes. In the technique disposable absorbent articles with different designs are known. For example, U.S. Pat. No. Re. 26,151 entitled "Disposable Diaper", issued to Duncan and Backer on Jan. 31, 1967, describes a conventional disposable diaper which has enjoyed great acceptance throughout the world and has been commercially successful. In addition, U.S. Pat. No. 4,964,860 entitled DETACHABLE TWO-PIECE ABSORBENT GARMENT, issued to Gipson and others on Oct. 23, 1990 describes an absorbent article with a band. U.S. Pat. No. 5,246,433 entitled ELASTICIZED DISPOSABLE TRAINING PANT AND METHOD OF MAKING THE SAME, issued to Hasse and others on Sep. 21, 1993 describes a unitary disposable absorbent article which can be used as training pants. Nevertheless, absorbent articles currently available to the public fail to provide many of the benefits which can be obtained with absorbent articles that have elastic gripping elements to allow the user to select the design of a diaper most appropriate for each particular use.
In the current market, the consumer has innumerable different basic designs of absorbent articles such as diapers to choose from, depending on the different options, comfort and cost, including conventional diapers, diapers with a band and training pants of the "pull-up" type. Conventional designs of diapers are generally of a type less expensive to produce and are generally accepted for use by babies and the sick or persons who in one way or another are bed-ridden. A conventional diaper adjusts to the user, first placing the rear portion of the diaper under the user (generally, the rear portion of the diaper is placed under the gluteal region of the body and the rear waist of the user) and then the rest of the diaper is pulled through the user's legs. The rear portion of the diaper is then connected to the front waist portion of the diaper over each side of the user by gripping means. Nevertheless, said conventional configurations tend to be very difficult to use, when the user refuses to remain still during the time the diaper is being applied. Moreover, adult users normally find that absorbent articles of the conventional type are difficult to put on by themselves without help. In addition, the configuration of the absorbent article lacks an easy inspection method without the complete removal of the absorbent article.
Diapers with a band have been introduced to overcome certain of the problems existing with conventional-type diapers. Diapers with a band are generally adjusted to the user by placing the diaper in such manner as to allow the band to be adjusted around the user's waist and the rest of the diaper hanging down between the user's legs. The portion of the diaper that hangs from the waist is then pulled through the legs of the user and connected to the the band portion of the diaper close to the waist. This way, the diaper with band can be adjusted to users who are standing and can be easily inspected to see if it is dirty without completely removing the diaper. In addition, adult users regularly find that the designs of absorbent articles with a band are much easier to put on without assistance. Nevertheless, as a general rule diapers with a band are more costly than conventional diapers and some users prefer the conventional design to the design with a band.
The trend of manufacturers to provide products that significantly improve the comfort provided to users is reflected, for example, in the generation of products which on the outside give the appearance of clothing (East Coast of the United States, at the beginning of 1995, according to the magazine Nonwovens Industry, page 39, January 1995 edition), and lateral elastic ties which provide the user with an anatomical adjustment.
European patent No. 0 532 035 issued to Zehnerm Rosch, Odorzynski, Siebers and Blenke on Mar. 17, 1993, entitled "absorbent article for recently born babies, adjustable in length by a foldable absorbent panel at the front side of the diaper and adjustable at the baby's waist by means of ear members that can be overlapped, one over the other and tied at the front of the diaper", is an example of said trend.
European patent No. 0 532 034 issued to Mary Bruemmer on Mar. 17, 1993, describes a disposable absorbent garment which includes a pair of ear members stretchable differentially, composed of an inner stretchable section and an outer stretchable section.
The above mentioned European patents refer to gripping elements that allow the article to adapt, by tension, to the user's waist. However, they do not mention the disadvantages of the effect of the continual movement of the user in respect to the adjustments at the waist; that is, the slipping away of the absorbent core from the areas to be protected.
U.S. Pat. No. 5,383,871 issued to Edward Carlin on Jan. 24, 1995 claims absorbent articles containing a fastening system that provides a sustained dynamic adjustment.
A wide range of fastening systems for absorbent products is known in the state of the art, particularly elastic gripping means to hold the absorbent article to the user's waist, and provide an anatomical adjustment, as claimed in U.S. Pat. No. 4,051,853 entitled "DIAPER WITH EXTENSIBLE FASTENER", issued to Francis L. Egan Jr. on Oct. 4, 1977; U.S. Pat. No. 4,066,081 entitled DIAPER WITH EXTENSIBLE FASTENER, issued to Charles H. Schaer on Jan. 3, 1978; U.S. Pat. No. 4,787,897 entitled STRETCHABLE FASTENING TAPE FOR DISPOSABLE DIAPER issued to Yasuhiro Torimae and others on Nov. 29, 1988; U.S. Pat. No. 4,795,456 entitled STRETCHABLE DIAPER TAB issued to Leo Borgers and others on Jan. 3, 1989; and U.S. Pat. No. 4,826,499 entitled ABSORBENT GARMENT HAVING LATERALLY DISPLACEABLE FASTENING MEANS issued to Nicholas A. Ahr on May 2, 1989. However, said gripping means described in the above mentioned patent have disadvantage in terms of their reduced capacity to stretch lengthwise and their retraction capacity.
Moreover, said anatomical adjustment concepts using stretch elements have been being applied together with traditional concepts of various sizes of absorbent products, containing very wide construction elements, which induces the consumer to confusion because of the presence of so many products on the shelves (up to 6 different stages of the same diaper), and increases the manufacturing cost, because of needing so much stock of raw material to prepare each one of these stages of absorbent products.
Recently, the Procter & Gamble company launched its diaper on the market under the brand "Pampers Uni Futur", which provides characteristics of a flexible fastening system (flexiband), reduction of materials on the outer and inner coverings (v.gr., the topsheet and the backsheet), core with a straight and shorter design than the traditional diaper, promoting in their marketing "perfect expansion and adaptation" to the body of babies. This product is offered at very competitive prices in respect to the other diapers for babies in the economic niche of the market. Nevertheless, the flexible concept offered by this product is very limited; since the flexiband element is formed by the napped joining of the polyethylene and polypropylene film, known as SELF woven (structural elastic like-film), the maximum stretching obtained at the time of fastening the diaper is approximately between 33% and 35% per flexible element. The results obtained in dynamic laboratories or consumers panels in samples of the general consumer in this niche showed negative acceptance results in the first instance, due to irritation problems of the skin caused by the friction of the flexiband, escape of liquids and solids because of the reduced length of the absorbent core, and the lack of adaptation to the bikini concept suggested by the product. This information was obtained from the report presented by the Sensor company in October 1995, which is incorporated by reference herein.
Other products that embodied elastic fastening elements were the diapers sold under the brands "Huggies Extratrim" and "Supreme" manufactured by Kimberly-Clark Corporation as claimed in U.S. Pat. No. 3,800,769 issued to E. Jacuba on Apr. 2, 1974, and U.S. Pat. No. 5,518,801 issued to Chappell on May 21, 1996. These products incorporate elastomer materials in the form of elastic bands which allow for a more comfortable adjustment to the baby's waist. Nevertheless, these elements are obtained from a coextrusion of materials, or through the connection of fusion and blown applied elastomers and provide a maximum stretching of only up to 75% in each gripping element (ultra-elastic). Nevertheless, these elastic fastening elements present a disadvantage on not offering respirability, since most of them are produced on the basis of laminations.
In the Nonwovens World magazine, Autumn 1993, Dr. Migaku Susuki in the publication of the Article "New Functional Material for Absorbent Products" stated that "improvements in cost performance include the combination of comfort with special materials and reduced weight and reduced quantity of raw materials in the finished product, in addition to the fact that consideration must be given to requirements for environment friendly products (social impact) and the need for innovation in the market". In another article published in the Nonwovens Industry magazine, January 1995, entitled "New Facility, New Concept for Hot-Melt Machinery Supplier", Dr. Carl Cucuzza states that "retailers pressured manufacturers searching for a quicker reply to purchase orders, products focused on the clients and improvements in the consistency and quality of the product. As a result, the manufacturers should balance efficiency against capital expenses, reduced inventories of the finished product and raw material, a reduction of wastes and idle time of equipment".
Notwithstanding the efforts made to manufacture an absorbent product with improved elasticity properties at the waist and respirability characteristics of the elastic gripping elements to adapt to the user's waist, the inclusion of elements that can provide elasticity percentages above 75% is advisable and necessary, limited by the elastomer materials described in the state of the art, in order to reduce the number of materials used in the manufacture of a diaper, without sacrificing adjustment and comfort.
Moreover, in line with the concept expressed by Dr. Susuki of "environment friendly", said materials should have "respirability" characteristics. In the Nonwovens World magazine, published in October 1993, Tim Woodbridge defined in an article that respirability "occurs when the delaying medium (air or water steam) can pass through the material membrane at such rate as to maintain an adequate balance for the designed final use". In the Spring of 1995, the company called Confab/ICD published an article in the Nonwovens World magazine, which announced a material which "is very similar to an elastic waist band" for its diaper for incontinent adults."
It would be advantageous to provide a disposable absorbent article such as a diaper with elastic gripping elements to allow the user to place and hold the absorbent article adjusted to and comfortable for the person's waist.
Consequently, the object of this invention is to provide an absorbent article with elastic gripping elements with superior elasticity characteristics, mainly in the fastening system, of up to 250% and increased respirability.
Another object of this invention is to provide an absorbent article which adjusts to the majority of users' sizes, ideally, 2 sizes thereof, not more than three.
Still another object of this invention is to provide an absorbent article substantially more economic than current conventional absorbent articles, but which embodies certain elements of the expensive absorbent articles.
Another object of this invention is to provide an absorbent article with a self adjustable gripping system designed to allow the absorbent article to be placed in a conventional configuration, or structured in such way as to form a type of pull-up training pants.
Still another object of this invention is to provide a disposable absorbent article that does not require material changes in the production lines.
These and other objects of this invention will be more easily observed by referring to the following description taken together with the attached drawings.